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# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserve.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import warnings
import paddle
import paddle.nn as nn
import paddle.nn.functional as F
from ppcls.utils import logger
class CELoss(nn.Layer):
"""
Cross entropy loss
"""
def __init__(self, epsilon=None):
super().__init__()
if epsilon is not None and (epsilon <= 0 or epsilon >= 1):
epsilon = None
self.epsilon = epsilon
def _labelsmoothing(self, target, class_num):
if len(target.shape) == 1 or target.shape[-1] != class_num:
one_hot_target = F.one_hot(target, class_num)
else:
one_hot_target = target
soft_target = F.label_smooth(one_hot_target, epsilon=self.epsilon)
soft_target = paddle.reshape(soft_target, shape=[-1, class_num])
return soft_target
def forward(self, x, label):
if isinstance(x, dict):
x = x["logits"]
if self.epsilon is not None:
class_num = x.shape[-1]
label = self._labelsmoothing(label, class_num)
x = -F.log_softmax(x, axis=-1)
loss = paddle.sum(x * label, axis=-1)
else:
if label.shape[-1] == x.shape[-1]:
label = F.softmax(label, axis=-1)
soft_label = True
else:
soft_label = False
loss = F.cross_entropy(x, label=label, soft_label=soft_label)
loss = loss.mean()
return {"CELoss": loss}
class MixCELoss(object):
def __init__(self, *args, **kwargs):
msg = "\"MixCELos\" is deprecated, please use \"CELoss\" instead."
logger.error(DeprecationWarning(msg))
raise DeprecationWarning(msg)